Dental hand piece



Jan. 30, 1945. N. RAYNE DENTAL HANDPIECE Filed Jan..2'7} 1945 A ttorney Patented Jan. 30, 1945 UNITED IsTATEs PATENT ,I'OFFICE DENTAL HAND PiECE Norman Rayne, London, England Application January 27, 1943, Serial No. 473,747

In Great Britain February 13, 1942 I 7 Claims. (01. 279-51) This invention relatesto dental handpieces, that is to say handpiece's adapted to hold and transmit rotary motion to the burrs used by dental surgeons in such'operations as the excasary that the mechanism be plentifully supplied with lubricating oil. The difliculty of dismantling and reassembling the priortypes of dental handpieces and the need for oil lubrication make it impossible for a dental operator to effect quick and thorough sterilization of a handpiece. In ordinary circumstances there is not time for dismantling. Moreover, the instrument cannot be boiled or soaked in an antiseptic solution since such steps would'destroy or remove the lubricating film.

An object of the invention is to provide an improved dental handpiece, and particularly to provide a handpiece that comprises only about half the customary number of component parts, and can be easily andlquickly disassembled and reassembled by any ordinarily intelligent person, without tools, and can be thoroughly sterilized without detriment to lubrication A dental handpiece, exhibiting the invention comprises a spindle rotatably supported in a casing, one end of the said spindle being adapted to be suitably attached to a driving shaft and the ther end thereof being tapered and hollowed and split to form a chuck, an interiorly coned socket being provided to co-operate with the said chuck, the said coned socket being so associated with the said casing as to be closely restrictedin' respect of its moving longitudinally of the said spindle and casing and being bored with a, taper corresponding to the taper of the chuck, the chuck and the conedsocket being so formed that the chuck by being pushed into the coned socket can be made to close to grip the shank of a dental burr if the said shank is placed within the chuck,

or to open again by being pulled out (of the coned socket, the coned socket being formed with a cylindrical exterior peripheral surface which is arranged to bear upon the inner surface of a forward cylindrical bearing suitably provided within chuck is pushed the casing, and means being provided for urging the spindle to move longitudinally s that the into or pulled out of the coned socket. v a

, Other features of the invention will beparticularly described hereinafter, and will be set forth in the appended claims. In order that the invention may be clearly understood and readily carried into effect, one embodiment thereof will now be fully describedtwith reference to the accompanying drawing, in which:

Figure 1 representsin elevation (enlarged) a 1 dental handpiece according to the invention; Figure 2 represents the same in sectional elevation; I

Figure 3 represents in perspective certain com onent parts; and N Figures 4 and 5 provide two views in sectional of the spindle H, .which end may be called the rear end, is adapted to be suitably attachedin known manner to a. driving shaft, such as one of the flexible shafts commonly used inconnection with dental handpieces. The other or forward end of the spindle H is tapered, hollowed and split to form a chuck |4 An interiorly coned socket I5 is provided to co-operate Withthe chuck l4, being bored with a taper corresponding to the taper of the latter, the chuck l4 and the coned socket l5 being so formed that the chuck M by being pushed into the coned socket I5can be made to closeto grip the shank of a dentaljburr if the said shank is placed Within the chuck I 4,

, or to open again by being pulled out of the coned socket l5. I The coned socket I5 is formed-with a cylindrical exterior peripheral surface, which is arranged to bear upon the inner surface of a'forward cylindrical bearing l6 which the casing l2 is suitably formed to receive. The forward cylindrical bearing I6 is preferably of the kind commonly referred to as self-oiling}? being of composite material impregnated with a suitable solid lubricant, such as graphite, grease or the like, so that this hearing is self-lubricating.

Aperforated closure nozzle I1 is provided at the forward end of the casing l2, the nozzle I] being perforated with a bore I8 concentric with the axis of the chuck I4, and havingan externally screw-threaded part [9 threaded in the end of the casing I 2 An equivalent closure might be constructed as a screw-on cap.

Means for urging the spindle II longitudinally so that the chuck I4 is pushed into or pulled out of the coned socket I5 comprise a control sleeve 2I adapted to be revolved in relation to the casing I2. The control sleeve 2| carries a bayonet pin 22 (Figure 3) adapted to engage with a bayonet groove 23 of helical or approximately helical form provided in an xtension sleeve 24 and rigidly attached to the casing I2 by being provided at its forward end with interior screw-threads 25 by means of which the extension sleeve 24 can be screwed upon an exteriorly screw-threaded portion 26 at the rear end of the casing I2. By means of the screw-threaded relationship thus provided, the extension sleeve 24 is longitudinally adjustable upon the casing I2.

The formation of the bayonet groove 23 is indicated in Figures 1 and 2, but is shown more clearly in Figures 4 and 5. The bayonet groove 23 at the forward end of its course is formed with a small notch or recess 2'! extending rearwardly, to provide that after the bayonet pin 22 has progressed relatively to the bayonet groove 23 and the casing I2 to the point at which it is nearest the chuck, then if it progresses slightly further in the bayonet groove 23 it is given room to recede slightly away from the chuck, by reason of its entering the notch 21. This arrangement provides that when by means of the control sleeve 2| the spindle II is moved forwardly, sufficient thrust can be applied to force the chuck I4 into the coned socket I5 so as to close the chuck, but by a slight further similar movement of the control sleeve 2I the compressive effect of this thrust is released so that the coned socket I5 can recede slightly to avoid being subjected to excessive friction tending to hinder its revolution.

In order to secure the extension sleeve 24 in rigid attachment to the casing Ii 2, suitable means are provided to lock the extension sleeve 24 in a chosen position in relation to the casing l2, as by a small screw joining these parts together. In the present embodiment the extension sleeve 24 is provided at its forward edge with several circumferentially arranged notchesZB with one of which engages the head of a smallscrew 28 fixed radially in the casing I2. The screw 29 when engaging with one of the notche 28 prevents the extension sleeve 24 from revolving in relation to the casing, :but is adapted to engage with different notches so as to allow of slight angular and longitudinal adjustment of the extension sleeve 24.' The longitudinal adjustment thus obtainable makes possible a very fine adjustment of the extent to which the chuck l4 enters into the coned socket I5 when the control sleeve 21 is operated to effect this movement of the chuck l4.

The spindle II near its end l3 supported in a rear bearing 30 which is associated with the casing I2 by being housed within the rear end of the control sleeve 2|. The bearing 30 is im pregnated with a lubricant so as to be self-lubricating. The rear bearing 30 abuts forwardly upon a flange 3I provided on the spindle II, and the rear end of the control sleeve H is interiorly screw-threaded to receive the forward end, correspondingly exteriorly screw-threaded, of an end ferrule 32 which is adapted to co-operate in the attaching of the spindle I I by its rear end I3 to a driving shaft, which end ferrule 32 when screwed home in the control sleeve 2| abuts with its forward end upon the rear end of the rear bearing 30. The arrangement is such that if the control sleeve 2| is so revolved that it is moved forwardly, i. e. in the direction of the chuck I 4, it carries with it the end ferrule 32, which accordingly pushes upon the rear bearing 30, which in turn pushes upon the flange 3 I, and the spindle II is thus moved longitudinally so that the chuck I4 can be pushed towards the coned socket I5.

The control sleeve 2I is so formed that a part of its interior constitutes an inwardly projecting shoulder 33 (Figure 2) which is arranged to abut upon the forward side of the flange 32. Thus if the control sleeve 2| is so revolved that it moves rearwardly it pushes upon the flange 3I,

not confined to thi field, but is also applicable to handpieces embodying any angular conformation. It will be obvious that the length of a handpiece as illustrated in the drawing could easily be considerably reduced, particularly in respect of the casing I2; moreover it would not be diflicult to modify and extend the end ferrule 32 so that the complete handpiece comprised two straight portions meeting at any desired angle.

What I claim and desire to secure by Letters Patent of the United States is:

1. A dental handpiece comprising, an elongated casing, a one-part spindle extending lengthwise within said casing with one end adapted to be attached to a driving shaft, a conical portion at the other end of said spindle being hollow and split to form a chuck, an internal annular flange carried by and within said casing, a removable member at the end of the casing having a bore therein aligned with said spindle, a cylindrical bearing within the casing between aid flange and said removable member, a socket member rotatable within said bearing and maintained against material movement longitudinally of the casing by said flange and said removable member, said socket member having an internal conical sur face corresponding to the taper of said spindle, and manually operable means for positively moving said spindle into said socket member and for positively moving the spindle way from said socket member.

2. A dental handpiece comprising, an elongated casing, a spindle extending lengthwise within said casing, a conical portion at one end of said spindle being hollow and split to form a chuck, an internal annular flange carried by and within said casing, a removable member at the end of the casing and having a bore therein aligned with said spindle, a cylindrical bearing impregnated with a lubricant mounted within the casing between said flange and said removable member, a socket member rotatable within said bearing and maintained against material movement longitudinally of the casing by said flange and said removable member, said socket member having an internal conical surface corresponding to the taper of said spindle, and manually operable means for positively moving said spindle into said socket member and for positively moving the chuck, an internal annular flange carried by and,

within said casing, a closure nozzle threaded within the end of said casing and having a bore I aligned with the axis of the chuck, a cylindrical bearing mounted within the casingbetwee-n said flange and said closure nozzle, a socket member rotatable within said bearing with one end thereof adapted to abut against said flange and the.

other end of said socket member being adapted to abut against said closure nozzle, said socket member having conical shaped internal surface corresponding to the conical shape of said spindle, and manually operable means for positively moving said spindle into said socket member and for positively retracting the spindle from within said socket member,

4. A dental handpiece comprising, an elongated casing including a sleeve adjustable lengthwise of the casing, a spindle extending lengthwise within said casing and sleeve, a conical portion at one end of said spindle and being hollow and split to form a chuck, an internal annular flange within said casing, a removable member at the end of the casing and having a bore therein aligned with said spindle, a cylindrical bearing within the casing between said flange and said removable member, a socket member rotatable within said bearing and maintained against material movement longitudinally of the casing by said flange and said removable 'member, said socket member having an internal conical surface corresponding to the taper of said spindle, a control sleeve rotatable with respect to said' casing and the first sleeve, said first sleeve having a-substantially helically arranged groove formed on the inner surface thereof, a bayonet pin carried by said control sleeve operable within said groove, and means associated with the control sleeve for positively moving the spindle longitudinally of the casing upon rotation of the control sleeve with respect to the casing.

5. A dental handpiece comprising, an elongated casing, a sleeve adjustably secured to the casing, a spindle extending lengthwise within said casing and said sleeve,.a conical portion at one end of said spindle being hollow and split to form a chuck, an internal annular flange carried by and extending within said first mentioned sleeve, a l

able member, a socket member rotatable within said bearing and maintained against material movement longitudinally of the casing by said flange and said removable member, said socket member having an internal conical surface corresponding to the taper of said spindle, a control sleeve rotatable with respect to said casing, the first sleeve having an approximate helical groove formed on the inner surface thereof, a bayonet pin carried by said control sleeve operable within said groove, means associated with the control sleeve for positively moving the spindle longitudinally of the casing upon rotation of the control sleeve with respect to the casing, said first sleeve having a longitudinally extending notch therein at one end of said helical groove whereby the bayonet pin may enter said notch to slightly retract the spindle from said socket member.

6. A dental handpiece comprising, an elongated casing including a sleeve threaded thereon adjacent one end of the casing, a spindle extending" lengthwise within said casing, a conical end portion on said spindle and being hollow and split to form a chuck, a cylindrical bearing within the casing adjacent saidconical portion of the spinbayonet pin on the control sleeve engaging the first sleeve within said helical groove, means associated with the control sleeve for moving the spindle longitudinally of the casing upon rotation of the control sleeve relative to the casing, a plurality of circumferentially spaced-openings in the first sleeve, and means carried by the casing for engaging the first sleeve in one of said openings.

7. A dental handpiece comprising, an elongated casing, a spindle arranged lengthwise within the casing, a conical portion at one end of the spindle being hollow and split to form a chuck, a bearing within the casing adjacent said conical portion, a socket member rotatable within said bearing and having an internal conical surface corresponding to the taper of said spindle, a sleeve forming an extension of said casing, said sleeve having a substantially helical groove therein, a control sleeve including a shouldered portion mounted within the first sleeve, a bayonet pin carried by the control sleeve for engaging the first sleeve within said groove, a flange on said spindle adjacent said shoulder, a bearing for the spindle mounted within said control sleeve and abutting said flange, and a ferrule member secured to the control sleeve abutting the other end of said bearing.

NORMAN RAYNE. 

